Note: Descriptions are shown in the official language in which they were submitted.
~ 327~12
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T}~e p~ ent in~r~nt.i~n i siix~c~e~ ~ app~ra~
~dapted to ~ 0lmted ~3n one or ~ore dlri~rqn ~heels o~ a
motor vehi~ ordex ~c~ inar~a~ tr~ ion. 2q~re
~5 pRr~ ularly, th~ pr~s~nt inYentis:~n co~p:rises ~ r~nv-
~bl~ tra~tiDn devic~ ~rhich can be used to ae!~ in
exltricating an autom~bile, t~ r oth~r vehicle from
mud, is:e or ~nowO ~: ~r~a~tion devic:e i~ ad~p~e~l tC~ ~it
~ variet~ ~f ti~ ~ize~ n be conv~ni~3ntl~ ~ored in a
ao ~notor vehicle ur~ 1 nee~l~d, ~r~d ~n ~e mountad and dis~
m4un~e~1 ola a whç~l wi~ t th~3 u~e of tool~;.
priar art i~; repl~o wit~h app~r~t~s inten~-
~d to ov~raom~3 th~ loss o~ tr~ ion *Ue to the e~ec~s
of i~ and snc~w. ~ny su~h de~ice~ ~r~ prophy~ctic in
~5 natllr4~, e~q~ 3s o~ e~ip~ent ~lesi~ned tc~
p~ t ~h~ v~hiale ~r~m l~0eo~ g ~us;~ com~hon
exa~pl~3 o~ suc:~ apparatus ar6~ au1to~oti~, anti-ækid ~ir~
c:hairle, wihi~ ar~ ds~ n~d to b~ ~noun~$~d on th~ drive
~he~ls ~ mnt~r ~ehicle at ~:h~ ons~t o~ ~sln~er and to
30 re~nain upon ~h~ v~ahicle ~or ~n e~tende~ p~riod o~
tim~ . NOt only are tire chair~s dî:~f ~c~ult ~ in~tall and
r~m4~, ~ut ~he~ ~re alæl generally n~c~e~sary ~r only
a ~ew wi~:er d~ys in ~any lo~ales.
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~327~12
Other examples of traction devices designed to
be mounted on a vehicle wheel prior to venturing into
ice and snow are found in the following prior art
patents, viæ., U.S. 2,-J22,260, and U.S. 4,244,412. A
common deficiency with such devices is that they are
typically quite difficult to attach to a vehicle wheel
after the car has become stuck or mired.
The prior art contains several devices which,
like the apparatus of the present invention, are
designed to be mounted on a pneumatic tire of a mired
auto or other vehicle to extricate the vehicle from ice,
snow or mud. A feature common to all of these prior art
devices is that they must be fairly precisPly engineered
i to fit the size and contour of the tire with which they
are utilized. In view of the variety of tire sizes in
use today, manufacture and inventory of a number of
sizes required to fit all vehicles in a difficult propo-
sition. Moreover, the cross~section (profile) of a tire
is highly dependent on the degree of inflation, which in
turn is temperature related. As a result, a device
designed to fit snuggly around a tire which is properly
inflated might very well be inappropriate to the same
tire in an under-inflated condition.
U.S. Patent 2,518,170 discloses a traction
device for a pneumatic tire comprising a pair of clamp
members pivotally joined at the road-bearing surface.
The device illustrated in this patent must be carefully
fitted to the tire since the device is adapted to be
mounted on the vehicle's tire rim. In addition, the
patent teaches that a tool is required to mount or dis-
` mount the device from the tire.
U.S. Patent 4,244,412 shows an anti-skid device
'~ formed of a plurality of inter-connected U-shaped
elements~ ~ike the apparatus of the present invention,
the apparatus illustrated in this patent employs an
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upwardly curving segment on the base of the U-shaped
device to transmit locking forces to the vertical
sections of the traction device in order to more closely
grip the sidewall of the tire on which it is mounted.
This patent teaches the necessity of a supplemental
apparatus to secure the device to the tire rim. More-
over, the device illustrated in the patent closely
follows the contour of the tire sidewall
U.S. Patent 2,625,193 depicts a multi-element
wire loop device adapted to be mounted on a pneumatic
tire. Like the 4,244,412 patent, this patent teaches
the desirability of utilizing an upwardly curving
surface of the traction device to provide better
gripping action. Additionally, the patent teaches the
use of protuberances along portions of the contacting
surface of the traction device to retain the device on
the tire. The device illustrated in this patent is
designed to closely mirror the geometry of the tire on
which it is mountedO
U.S. Patent 3,323,572 shows an anti-skid device
which utilizes an adhesive backing for mounting the
device to a tire. Although this apparatus can be
employed with a variety of tire sizes, the apparatus is
suitable ~or one-time use only, unlike the device of the
, 25 present invention which can be easily dismounted and
`` stored for re-use.
Summary of the Invention
.
The traction device of the present invention ;s
a unitary flexible apparatus having a base portion and
two up-standing side arms extending generally vertically
from the base portion, thereby defining an opening for
fitting the device to a wheel of a motor vehicle. The
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traction device base portion is adapted to be substan-
tially wider than the tread portion of the pneumatic
tire to which it is fitted in transver~e relationship,
thus providing a larger surface area for frictional
contact with a slippery surface such as mud, snow or
ice. The base portion also has a bendable~ upwardly
curving segment for contacting the tread portion of the
pneumatic tire.
Each of the traction device side arms has a
convex bottom section and an inwardly converging top
section for engaging the sidewalls o the pneumatic tire
on which the device is mounted. As the vehicle wheel is
rotated, the traction device comes into contact with the
ground and pressure is brought to bear on the upwardly
curving segment of the base portion. The resultant
force on the curved segment is transmitted through the
side arms to the pneumatic tire sidewalls. The effect
of the wider base portion and convex bottom section is
to intensify the gripping effects of the side arms. As
a result, the traction device wlll remain firmly
anchored to the vehicle wheelO
The traction device casl be manufactured from a
resilient material such as thin metal, or a thermo-
plastic or thermo-setting polymer or resin. If a
polymer or resin is employed~ the material can be rein-
forced with metal, ceramics or glass if desired. When
~, an injection molding process i5 utilized, preferred
materials for manufacturing the device include the
thermo-plastic acetal copolymers manufactured under the
tradename Celcon~ by the Celanese Corporation and
Delron~ by E.I. DuPont de Nemours & Co. and a glass-
i reinforced polyamide-imide containing resin marketed by
Amoco Chemicals Corporation under the trademark
Torlon~. Other materials and processes will be apparent
~5 to those skilled in the art.
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In order to achieve better frictional contact
with the sidewalls and tread portion of the tire, it may
be desirable to provide supplemental grip means along
the inside surface of the traction device such as serra-
tions or a flange or ridye.
Various other features and advantages of the
invention will become apparent from the following
detailed description when taken in conjunction with the
drawings.
:' 10
Brief Description of the Drawings
FIG. l is a side elevational view showing a
traction device according to the present invention
mounted transversely on a pneumatic tire.
FIG. 2 is a side elevational view of the
traction device of FIG. 1.
FIG. 3 is a cross-sectional view taken along
line 3-3 of FIG~ l.
~0 FIG. 4 is a sectional view taken along line 4-4
j of FIG. 2.
FIG. 5 is a sectional view taken alcng line 5-5
I of FIG. 2.
j FIG. 6 is a sectional view taken along line 6~6
of FIG. 2.
FIG. 7 is a side elevational view showing a
second embodiment of a traction device according to the
-`, present invention mounted on a vehicle wheel.
' FIG. 8 is a side elevation view of the traction
~ 30 device shown in FIG. 7.
'~ FIG. 9 is a cross-sectional view taken along
, line 9-9 of FIG. 7.
FIG. 10 is a fragmentary sectional view takes
along line 10-10 of FIG. 8.
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FIG~ ll is a side elevational view showing a
third embodiment of a traction device according to the
present invention mounted on a vehicle wheel.
FIGo 12 is a side elevation view of the
traction device shown in FIG~
FIG. 13 is a cross-sectional view taken along
line 13-13 of FIG~
FIG~ 14 iS a top view of the traction device
shown in FIG. 11.
FIG~ 15 is a partial bottom view of the
traction device shown in FIG. 11.
FIG. 16 is a side elevational view showing a
fourth embodiment Gf a traction device according to the
present invention mounted on a vehicle wheel.
FIG. 17 is a side elevation cross-sectional
view taken along line 17-17 of FIG. 16.
FIG~ 18 is a cross-sectional view taken along
line 18-18 of FIG. 17.
! FIG. 19 is a side elevation view of the cross
member of the traction device shown in FIG. 16.
FIG. 20 is a top view of the main member of the
traction device shown in FIG. 1~5.
FIG. 21 is a top view of the main member of the
traction device shown in FIG. 16.
i~ 25 FIG. 22 is a top view of the main member and
'~ the cross-member of the traction device shown in ~IG.
16.
Detailed Description of the Preferred ~mbodiments
:~ 3n
One embodiment of a unitary traction device 20
in accordance with the present invention is shown in
FIGS 1-6~ Traction device 20 is adapted to be trans-
- versely mounted on a pneumatic tire 21 which is attached
~; 35 to a vehicle drive wheel 22 at rim 25 ( FIG~ 3)~
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Pneumatic tire 21 has a pair of sidewalls 23ar23b and a
tire tread portion 24.
Traction device 20 is fashioned from a
resilient material to form a substantially U-shaped
structure having a base portion 26, and a pair of side
arms 27a~27b extending generally vertically from base
portion 26. Base portion 26 is substantially axially
wider than the tread portion 24 of tire 21 and has an
upwardly curving segment 28 which, when mounted on tire
21, bears against a road~engaging surface 29 of tirP
tread 24.
Traction device side arms 27a, 27b have
respective convex bottom portions 29a, 29b and inwardly
curving top sections 30a, 30b. Traction device side
arm 27b is longer than arm 27a and can be easily grasped
to mount and dismount device 20. The longer side arm
also provides additional surface contact to minimize
rotation and prevent dislodging. When traction device
20 is mounted on tire 21 (FIG 3), the convex bottom
portions 29a, 29b cooperate with base portion 26 and
pneumatic tire 21 to define a pair of pockets 31, 32.
In FIGo 2~ resilient traction device 20 is
shown in a normal, relaxed position and the distance
between side arms 27a, 27b is minimal. In order to be
mounted on tire 21, side arms 27a, 27b are pulled apart
to a wider position. As a result, when placed on tire
21 in the position shown in FIG. 3, side arms 27a
- and ~7b exert inward pressure against pneumatic tire
sidewalls 23a and 23b~ This pressure or tension serves
to hold device 20 in place on tire 21.
As the full weight of the vehicle is brought to
bear on drive wheel 22 and traction ~evice 20, it is
~, yenerally desirable to provide additional gripping
'~ action between sidewalls 23a, 23b and side arms 27a,
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27b. This gripping action is provided by the inter-
action of bottom portion upwardly curving segment 28 and
side arm convex bottom portions 29a, 29b. The weight of
the vehicle (not shown~ exerts a flattening effect on
curving segment 28 which is translated through and
causes movement of bottom portions 29a, 29b which causes
further movement of side arm top portions 30a, 30b. The
fact that traction device base portion 26 is wider than
tire tread portion 24 results in the fulcrums for these
forces being spaced apart from road-engaging surface 33
of tire 21. As a result~ greater gripping forces are
transmitted by the downward action of tire 21 on curving
segment 28, through the area of convex bottom portions
29a, 29b to sidewall gripping side arms 23a, 23b. Thus,
device 20 is particularly adapted to respond to
increased pressure by providing ~reater gripping action.
-¦ Referring now to FIGS 2 and 4-6, device 20 has
a strengthening rib 37 extending around an inner surface
35 thereof. Additional frictional engagement between
device 20 and tire sidewalls 23a, 23b and tread 24 can
l be obtained by the use of supplemental gripping means
¦ such as serrations 34 along inner surface 35.
! FIGS 7-1~ illustr~te a second embodiment of a
j resilient traction device 40 according to the present
invention, having a pair of sidearms 47a, 47b which are
substantially e~ual in size and do not extend beyond
wheel rim 25. Traction device 40 has a rib or vertical
flange 57 extending continuously along the inner
surface 55 thereof. Vertical flange 57 exerts a biting
action on tire tread 24 when downward pressure is
brought to bear on wheel 22. The operation of device 40
(FIG. 8) when mounted on tire 21 (FIG. 9) is similar to
that of device 20 (FIGS. 2 ~ 3), as described above.
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FIGS. 11-15 show a third embodiment of a
resilient traction device according to thP present
invention, having a pair of side arms 67a, 67b which are
substantially equal in size and do not extend beyond
wheel rim 25~ Traction device 60 further has a cross
portion 63 that extends from and is substantially
perpendicular to the base portion 66. The cross portion
63 is situated at approximately the center of the base
portion 66 and its upwardly curvin~ segment 68.
Further, the portion 63 extends outwardly and upwardly
from the base portion 66. Additionally, the cross
portion 66 has a plurality of outwardly extending knobs
61a, 61b on both its top surface and its bottom
surface. Each knob 61a, 61bis preferably cir~ular at
its base and conical in shape so as to form a point at
its outermost point. ~urther still, cross portion 63
can be tapered in as it extends in the outwardly
directionO The operation of the device 60 is also
similar to that of the device 20 and the device 40 as
described above.
FIGS. 16-22 show a fourth embodiment of a
resilient traction device according to the present
invention, having a pair of side arms 87a, 87b which are
substantially equal in size and do not extend beyond the
wheel rim (not shown). The traction device 80 further
has a separate cross member 90 that fits onto a main
member 81.
The cross member 90 has a first side 91 and a
second side 92. The first side 91 is preferably curved
and smooth. The second side 92 is preferably curved and
has a plurality of serrations 94. The cross member 90
can be constructed out of the same materials as the
traction device and discussed previously. Additionally,
the cross member 90 has a slot section 93 for receiving
the main member 81. The main member 81 further has a
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1327~2
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cross portion 83 that extends from and is substantially
perpendicular to the base portion 86. The cross portion
83 is situated at approximately the center of the base
portion 8~ and its upwardly curving segment 88.
Further, the portion 83 extends outwardly from the base
portion 86. Each side of each portion 83 has angled
surfaces 88 and a flat surface 89 for receiving the
cross member 90. A central rib 100 extendiny on an
inner surface 102 thereof and further having an indenta-
tion lOl is provided to better hold the cross member 90
to the main member 81. Thus, the main member 81 can be
threaded throush the slot section 93 of the cross member
90 until the cross member 90 locks. At such locking
point, central rib 100 presses against the side of
l 15 member 90 and indentation lO1 is situated within the
:' slot 93.
he further operation of this device 80 is
similar to that of the devices 20, 40 and 60 described
above.
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